| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device capable of accurately determining the abnormality of a downstream side passage for detecting differential pressure between upstream side pressure and downstream side pressure of DPF, even if an exhaust flow is small. <P>SOLUTION: An exhaust volume flow dvol is calculated according to an engine operation state (S11 to S13), and a change degree parameter ahat indicating change characteristics of detection differential pressure ΔPdpf to changes of the exhaust volume flow dvol is calculated (S14 to S17). Estimated particulate collecting amount Mpm of the DPF is calculated according to the engine operation state, and a determining threshold Thr is calculated according to the estimated particulate collecting amount Mpm (S18, S19). When the change degree parameter ahat is larger than the determining threshold Thr, it is determined that abnormality is occurred (S20, S21). <P>COPYRIGHT: (C)2009,JPO&INPIT |
